Non-volatile memory systems, such as flash memory, have been widely adopted for use in consumer products. Flash memory may be found in different forms, for example in the form of a portable memory card that can be carried between host devices or as a solid state disk (SSD) embedded in a host device. Flash memory may be written in pages and erased in blocks, so once a page is written, a rewrite may require the whole block to be erased. Rewrites may be necessary if there is a write error or failure. For example, NAND defects including broken word lines (WL) or wordline to wordline (WL-WL) shorts may result in data errors. In some instances, a portion of memory may be completely discarded despite being at least partially useable. Discarded memory may be reclaimed if the quality and performance of the discarded memory can be optimized.